Final answer:
The correct answer is a database, which is a structured collection of data designed for easy access and querying. Software like Microsoft Access enables users to manage and quickly retrieve data on specific topics.
Step-by-step explanation:
A user can gain instant access to a vast quantity of computer files related to a single topic through a database. Databases are structured collections of data that can be easily accessed, managed, and updated. Software like Microsoft Access is an example of database user interface and query software that allows users to manage data effectively.
While other options like social media can also connect users to a large quantity of information, they are not designed for structured queries or instantaneous access to files on a specific topic. A database is specifically designed for this purpose, providing the ability to search, filter, and retrieve information quickly and efficiently, thanks to its organized structure and powerful querying capabilities.